Views: 4 Author: Site Editor Publish Time: 2020-04-01 Origin: Site
Anodized aluminum Tubing with its unique technology and has been named, and get the majority of merchants, significantly improve the corrosion resistance of aluminum tube, also make the aluminum tube with one of the reasons for a variety of colors. If you want to have a comprehensive understanding of this commodity, welcome to read this article.
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Definition Of Anodized Aluminum Tubing
Principle Of Anodized Aluminum Tubing
Classification Of Anodized Aluminum Tubing
Anodic alumina tube refers to the aluminum tube surface coated with a layer of dense alumina, to prevent further oxidation, chemical properties and alumina of anodizing aluminum tube is the same. However, unlike ordinary oxide films, anodic alumina of anodizing aluminum tube can be dyed by electrolytic coloring.
Aluminum or aluminum alloy products as the anode, placed in the electrolyte solution for power treatment, the use of electrolysis to make the surface of the formation of aluminum oxide film process, known as aluminum tube anodic oxidation treatment. After anodizing treatment, the surface of the aluminum tube can generate a compact oxide film with thickness ranging from several microns to several hundred microns. Compared with the natural oxidation film of aluminum alloy, corrosion resistance of anodizing aluminum tube, wear resistance and decorative properties are obviously improved.
The principle of anodic oxidation of aluminum tube is essentially the principle of electrolysis. When the current passes through, the following reaction will occur:
On the cathode, H2 is released by the following reaction: 2H + + 2e H2
On the anode, 4oh-4e 2H2O + O2, the oxygen precipitated is not only molecular oxygen (O2), but also atomic oxygen (O), and ionic oxygen (o-2), usually represented by molecular oxygen in the reaction.
As an anode, aluminum is oxidized by the oxygen precipitated on it to form an anhydrous Al2O3 film: 2AI + 3[O] = AI2O3 + 1675.7kj
It should be noted that the resulting oxygen does not react entirely with the aluminum, and some of it is precipitated in gaseous form during production of anodizing aluminum tube.
Anodic oxidation has been widely used in industry aluminum tube production for a long time. There are various methods under different names, which can be summarized as the following classification methods:
Phosphoric acid anodic oxide film is porous with a relatively large pore size and a film thickness of about 2 ~ 5 m. Among various anodic oxidation processes, phosphoric acid anodized adhesive has the highest bonding strength as the pretreatment before bonding of aluminum tubes. Therefore, phosphoric acid anodic oxidation is often used for anodizing aluminum tube components to be bonded. It is a very special anodic oxidation technique.
The anodic oxidation process of chromic acid is a traditional process. The oxide film obtained by chromic acid anodized aluminum tube is thinner than that obtained by sulfuric acid anodized aluminum tube, generally only 3 ~ 5um, but the thin film does not affect the assembly of precision parts, and it can maintain the accuracy of the original aluminum tube, with good elasticity.
In addition, the chromic acid anodic oxidation electrolyte has a small solubility to aluminum. If there are electrolyte residues in the blind holes and slits of aluminum pipes, it has little influence on its corrosion, so it is suitable for castings, riveting and welding parts.
Sulfuric acid anodization is a common method for surface treatment of aluminum tubes. In recent years, many researches have been made by domestic and foreign counterparts in order to improve the quality of oxide film, increase the rate of film formation, expand the operating temperature range and reduce energy consumption. According to the dyeing properties of various anodic oxidation films, only the oxidation film obtained by sulfuric acid anodization aluminum tube is the most suitable for dyeing.
Sacrificial anode means that the anode is gradually consumed with the outflow current when the theoretical metal of the electrolytic cell is used as the anode. Sacrificial anodes are usually used economically only in structures with low protection current requirements and in environments with low soil resistivity like anodizing aluminum tube.
The sacrificial anode is suitable for cathodic protection of metal corrosion in ships, mechanical equipment, marine engineering and seaport facilities, as well as aluminum pipes and cables in sea mud.
Metal or alloy parts are used as anodes, and aluminum tubes are made into oxide films by electrolysis. The above is the introduction of anodized aluminum tube, hope to help you. There will be more research into electrolytic areas in the future. For more information, welcome to visit our website.